144 Scientific Proceedings, Royal Dublin Society. 
EXPLANATION OF PLATE VIII. 
[All the figures are from specimens of Hemitrypa hibernica, from Garden- 
field, near Tuam, Co. Galway. | 
Fics. 
1. Transverse section, viewed by transmitted light, showing four 
branches or columns, each with its pair of zoccia. One of the 
zocecia shows the aperture, directed towards the tegmen. In 
three cases a pillar-like process has been traversed, the outer ex- 
pansion of which forms part of the tegmen. The primary ribbed 
reverse of the columns, with the more opaque secondary thicken- 
ing, can be well seen. x 20. 
2. Vertical section, viewed by transmitted light, showing the reverse 
on the left, and the zocecia, with the pillars that support the teg- 
men, on the right. The tegmen itself is lost. x 30. 
8. Dissection of a thin slice, viewed obliquely, showing the ribbed 
columns, from which the secondary deposit has been broken away ; 
the inner face of the tegmen is seen on the right, and a transverse 
section of the whole structure occurs on the surface of the slice. 
Three dissepiments are also seen. x 8.’ 
4. Section of limestone, viewed by reflected light, showing parts .of 
several zoaria, crowded together, in various stages of growth. x 4. 
5. External view of a zoarium, the tegminal apertures being barely 
visible to the naked eye. In the upper left-hand portion the teg- 
men has been broken away, and the fenestrules, with remnants of 
the columns, can be seen. Natural size. 
